Presentation
Patient is brought into the emergency department after a motor vehicle accident.
Patient Data
The radiograph is underpenetrated, but one can still see widening of the symphysis pubis and of the left sacroiliac joint. This is compatible with a pelvic ring injury and CT of the pelvis is the next step to look for any other fractures that may not be visible on the radiograph. The CT revealed an additional right sacral fracture, difficult or impossible to see on the radiograph.
The CT is also useful to look for pelvic visceral or arterial injury (e.g. the left superior gluteal artery).
Annotated image of the original trauma radiograph:
- the red arrow points to widening of the left sacroiliac joint (compare with the contralateral joint)
- the yellow arrow points to diastasis of the symphysis pubis
- the right sacral fracture is invisible
- the pubic bones are intact
Because of the unstable pelvic ring fracture, the patient underwent reduction and fixation of the pelvic ring fractures.
Post open reduction and internal fixation of the pelvic ring fractures:
- supra-acetabular pedicle screws are connected anteriorly with a spinal rod
- cannulated screws through the sacroiliac joints fuse the posterior pelvis
Case Discussion
This pelvic ring fracture is predominantly an open book type (AP compression), but the right sacral fracture seen on CT shows there was a lateral mechanical force also involved in the injury. The combination of the unilateral AP compression injury with a contralateral lateral compression injury is the definition of a "windswept pelvis", although the lateral compression injury component in this case is subtle.
Pelvic ring fractures are unstable injuries and internal fixation is warranted.